Django：强制管理员用户在TabularInline中输入至少一个项目

Question

在我的管理员对象Chair我有一个TabularInline对于任意数量的Desk对象。我希望每个Chair始终至少有一个与之相关联的对象Desk。有没有办法让管理界面强制用户输入至少一个Desk？如果没有输入Desk，就显示错误？

Answer 1

马修弗拉纳根有一个很好的例子，说明如何在一个formset中需要一个有效的表单：http://code.google.com/p/wadofstuff/wiki/WadOfStuffDjangoForms和http://wadofstuff.blogspot.com/2009/08/requiring-at-least-one-inline-formset.html 希望能帮助你。

Answer 2

一个通用的表单集中clean()方法用于需要的至少一个项目：

def clean(self): 
     """Check that at least one service has been entered.""" 
     super(MyFormSet, self).clean() 
     if any(self.errors): 
      return 
     if not any(cleaned_data and not cleaned_data.get('DELETE', False) 
        for cleaned_data in self.cleaned_data): 
      raise forms.ValidationError('At least one item required.') 

这应为纯的formsets，模型和表单集在线模型表单集工作。

Answer 3

使用akaihola的答案，这里是一个更完整的例子：

添加到您的forms.py：

from django import forms 
from django.forms.models import BaseInlineFormSet 

class AtLeastOneRequiredInlineFormSet(BaseInlineFormSet): 

    def clean(self): 
     """Check that at least one service has been entered.""" 
     super(AtLeastOneRequiredInlineFormSet, self).clean() 
     if any(self.errors): 
      return 
     if not any(cleaned_data and not cleaned_data.get('DELETE', False) 
      for cleaned_data in self.cleaned_data): 
      raise forms.ValidationError('At least one item required.') 

，然后在你的admin.py：

class DeskInline(admin.TabularInline): 
    model = Desk 
    formset = AtLeastOneRequiredInlineFormSet 

class ChairAdmin(admin.ModelAdmin): 
    inlines = [DeskInline,] 

admin.site.register(Chair, ChairAdmin)